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Stinging nettle (Urtica dioica L.) is a perennial plant species that is often perceived as a weed, but in recent years it has attracted interest for its medicinal and nutritional properties. Wild nettle is primarily a variable plant material of unexplored composition, so recent research aims to the importance of its cultivation. Optimal yield and nutritional quality of the final product are influenced by a number of abiotic, biotic and anthropogenic factors, which are difficult to control due to fluctuating environmental conditions during field cultivation. Modern greenhouse hydroponic cultivation techniques, such as floating hydroponics, can eliminate the problems of field cultivation and allow earlier harvesting, higher yields and better quality of plant material. Optimal conditions for plant growth are achieved by proper management of the abiotic factors of air and nutrient solution during cultivation. Since different plant species differ considerably in their uptake of certain nutrients, it is necessary to determine the optimum composition of nutrient solution for each species depending on the cropping season and the purpose of the final product. The aim of this study was to determine the specialized metabolites and antioxidant properties of fresh nettle leaves depending on the content of two different nutrient solutions (EC 1.8 mS cm -1 and EC 3.0 mS cm -1) in floating hydroponics. The nutrient solution with the lower amount of nutrients resulted in higher levels of total phenolics (238.4 mg GAE 100 g-1) and lower levels of vitamin C (80.3 mg 100 g -1) and antioxidant capacity (2413.8 μmol TE L -1).

The aim of this study was to assess the nutritional composition of fruits of some citrus species (sweet orange, grapefruit, clementine and kumquat) and to determine their basic physicochemical parameters, bioactive compounds content, and antioxidant capacity. According to the analyzed data, kumquat fruits had the highest dry matter content (18.71%) and total acid content (3.08%), while the highest values of total soluble solids (13.41%), pH value (3.92), vitamin C (53.69 mg/100 g FW), total phenols (162 mg GAE/100 g FW), β-carotene (1053.17 µg/100 g FW), and antioxidant capacity (1.70 mmol TE/kg) were determined in clementine fruits. Considering the nutritional composition of citrus fruits, it can be concluded that they are a rich source of various bioactive compounds, especially vitamin C, carotenoids, and polyphenols, and are characterized by their high antioxidant capacity, which is important for health. Moreover, the cultivation of citrus fruits is an important factor in the Croatian economy, which should be promoted in the future, and the potential of the southern part of Croatia for the cultivation of these citrus fruits should be exploited to the maximum., Cilj ovog istraživanja bio je valorizirati nutritivni sastav plodova određenih vrsta citrusa: slatke naranče, grejpa, klementine i kumkvata, analizirajući njihova osnovna fizikalno-kemijska svojstva, sadržaj bioaktivnih spojeva i antioksidacijski kapacitet. Prema analiziranim podacima, plodovi kumkvata imali su najviše vrijednosti ukupne suhe tvari (18,71%), ukupnih kiselina (3,08%), dok su istodobno u plodovima klementine utvrđene najviše vrijednosti topljive suhe tvari (13,41%), pH vrijednosti (3,92), vitamina C (53,69 mg/100 g FW), ukupnih fenola (162 mg GAE/100 g FW), β-karotena (1053,17 µg/100 g FW) i antioksidacijskog kapaciteta (1,70 mmol TE/L.) Temeljem analiziranih parametara nutritivnog sastava plodova različitih vrsta citrusa može se zaključiti kako su agrumi bogat izvor različitih bioaktivnih spojeva, posebice vitamina C, karotenoida i polifenola, pa ih stoga karakterizira i visok antioksidacijski kapacitet, a što je od iznimne važnosti i za zdravlje ljudi. Štoviše, uzgoj agruma važan je čimbenik u hrvatskom gospodarstvu, koji bi trebalo dodatno promovirati, dok potencijal južnog dijela Hrvatske za uzgojem ovih agruma treba maksimalno iskoristiti.

The hydroponic ebb and flow system is a modern technique most commonly used for growing leafy vegetables. It involves periodic flooding and draining of the nutrient solution, which allows controlled drought stress. Abiotic stress can positively affect the accumulation of plant polyphenols with high antioxidant activity. Stinging nettle is a perennial wild plant that can be consumed as a green leafy vegetable due to its nutritional value. The aim of this research was to determine the content of total phenolics (TP), flavonoids (TF), non-flavonoids (TNF) and antioxidant capacity of stinging nettle leaves grown in ebb and flow system under different irrigation intervals. The experiment was conducted in a greenhouse during the spring growing season. Plants were treated with a nutrient solution for one hour and then exposed to three different drought intervals of 24, 48, and 96 hours. During the irrigation interval of 48 hours, plants accumulated the highest amounts of TP (400.21 mg GAE/100 g), about 23% more than when plants received no nutrient solution for 24 hours, and even about 30% more than when the plants were not irrigated for 96 hours. Also, the values of antioxidant capacity were highest during the 48-hour irrigation interval. The obtained results suggest that stinging nettle accumulates the most phenolic compounds during the 48 hour stress caused by the absence of nutrient solution.

The ebb and flow system is a hydroponic technique for growing plants that allows rational water use and management of water stress to obtain plant material rich in bioactive compounds. The risk with this technique is the lower yield and the deterioration of the morphological characteristics of the cultivated plants that can occur. The aim of this study was to determine the effect of 2 intervals of irrigation intervals on the agronomic traits of stinging nettle in 2 harvest periods. The combination of 48 hours of water stress and the 2nd harvest period gave the highest yield (1.21 kg m-2), while the combination of 72 hours of water stress and the 1st harvest period resulted with the lowest nettle yield (0.65 kg m-2).

Asimina triloba (L.) Dunal, commonly known as paw-paw is the only temperate fruit species in the family Anonacae of the genus Asimina, otherwise characteristic of tropical climates. Asimina triloba L. is the species with the largest edible fruit native to North America. Even in native areas of this species, the fruits are mostly collected from wild populations, while commercial cultivation is limited to small private orchards. The fruits of this species are becoming increasingly popular, mainly because they have great potential for fresh consumption, but also for processing, and have a number of beneficial effects on human health. The fruits of paw-paw are characterized by high energy value, but also by high nutritional potential, as they contain significant amounts of various vitamins, minerals, and other phytochemicals important for human health. Since there are also small orchards of this species in the Republic of Croatia, the aim of this work was to determine the nutritional potential, bioactive compound content, and antioxidant capacity of the paw-paw fruits from different growing areas in Croatia. All analyzed paw-paw fruits from Croatia are characterized by a high content of dry matter (average value regardless of location 23.76%) and high values of total sugars (average value 20.11%). According to the analyzed bioactive compounds, the fruits also contain high values of vitamin C (average 35.69 mg/100 fw), total phenols (average 224.02 mg GAE /100 g fw), and β-carotene (average 95.62 µg /100 g fw), as well as high values of antioxidant capacity (average 2412.92 µmol TE/L). According to the analyzed physicochemical parameters, paw-paw fruit can be considered as a nutritionally valuable raw material, and all the studied locations (mainland and coastal Croatia) are suitable for cultivation of this fruit species with significant nutritional, biological, and functional potential.

Cilj ovoga rada bio je utvrditi promjene sadržaja bioaktivnih komponenti tijekom proizvodnje suhog praha maline kao i utjecaj temperature sušenja na kvalitetu finalnog proizvoda. Plodovi malina s početnim udjelom vode od 87, 17 % osušeni su u laboratorijskom sušioniku „INKO” ST40 pri temperaturi od 40 °C i atmosferskom tlaku 1013 hPa do postizanja sadržaja vode od približno 15 %. Iz dobivenih rezultata vidljivo je da tijekom proizvodnje suhog praha u finalnom proizvodu došlo do smanjenja udjela vitamina C za 85, 59 %, ukupnih fenola za 32, 32 %, flavonoida za 40, 09 %, neflavonoida za 24, 61 %, antocijana za 2, 78 % i antioksidacijskog kapaciteta za 18, 98 %. Stoga se može zaključiti da parametri sušenja značajno utječu na sadržaj analiziranih bioaktivnih spojeva.

Cilj rada bio je analizirati i usporediti nutritivnu kvalitetu mutnih, svježe cijeđenih sokova iz plodova četiriju različitih sorti jabuka: 'Idared', 'Jonagold', 'Golden Delicious' i 'Cripps Pink'. S obzirom na analizirani mehanički sastav utvrđeno je da najbolje iskorištenje ploda za dobivanje soka ima sorta 'Idared' (45,51%), zatim slijedi sorta 'Golden Delicious (44,22%), 'Jonaglod' (36,56%) te sorta 'Cripps Pink' (25,75%). Prema rezultatima dobivenim u ovom istraživanju sok sorte 'Golden Delicious' pokazuje najveći omjer TST/UK, zatim sok sorte 'Jonagold', 'Idared', dok je najmanji omjer utvrđen kod soka sorte 'Cripps Pink'. Najveći sadržaj vitamina C (6,75 mg/100g svježeg ploda) kao i najveći sadržaj ukupnih fenola (55,84 mgGAE/100 g svježe tvari) utvrđeni su u soku sorte 'Jonagold' Temeljem dobivenih rezultata može se zaključiti da su plodovi svih istraživanih sorti pogodni za proizvodnju mutnog soka, ali i da mogu biti dobra podloga za proizvodnju ostalih sokova od raznih vrsta voća, The aim of the study was to analyse and compare the nutritional quality of cloudy, freshly squeezed fruit juices from four different apple cultivars: ‘Idared’, ‘Jonagold’, ‘Golden Delicious’ and ‘Cripps Pink’. Considering the analysed mechanical composition, it was determined that the best yield of fruit for juice production has the cultivar 'Idared' (45.51%), followed by the cultivar ‘Golden Delicious’ (44.22%), 'Jonaglod' (36.56%) and the 'Cripps Pink' cultivar (25.75%). According to the results obtained in this study, the juice of the 'Golden Delicious' cultivar shows the highest TST/UK r atio, followed b y t he j uice o f t he 'Jonagold' a nd 'Idared' cultivars, while the lowest ratio was found for the juice of the 'Cripps Pink' cultivar. The highest content of vitamin C was determined in the juice of the cultivar 'Jonagold' (6.75 mg/100 g of fresh fruit) as well as the highest content of total phenols (55.84 mg GAE/100 g of fresh matter). Based on the obtained results, it can be concluded that the fruits of all investigated cultivars are suitable for the production of cloudy juice, but also that they can be a good base for the production of juices from various types of fruit.

Dvodomna kopriva (Urtica dioica L.) je u novije vrijeme nepravedno zapostavljena biljna vrsta, posebice kao prehrambena namirnica. Zbog dokazanih nutritivnih i ljekovitih svojstva, svrstava se u kategoriju funkcionalnih namirnica. U fazi intenzivnog porasta ima velike potrebe za dušičnim gnojivima što može umanjiti kvalitetu finalnog proizvoda, pa se istražuju preprati dozvoljeni i u ekološkom uzgoju. Biostimulatori su proizvodi prirodnog porijekla koji imaju efikasnu primjenu kod biljaka u stresnim uvjetima ublažavajući nepovoljne čimbenike tijekom uzgoja. U ovome radu istražene su potencijalne koristi od primjene biostimulatora na morfološke pokazatelje i osnovni kemijski sastav koprive. Monofaktorijalni poljski pokus postavljen je na dvogodišnjem usjevu koprive po metodi slučajnog bloknog rasporeda u tri repeticije. Nasad je tretiran s četiri različita biostimulatora (Humistar, Phylgreen, Aminovital, Delphan Plus) u usporedbi s kontrolnom varijantom. Biostimulatori nisu imali opravdani utjecaj na morfološke pokazatelje niti na ukupni prinos, no imali su različit utjecaj na razinu minerala i specijaliziranih metabolita u biljci, pri čemu se mogu se izdvojiti proizvodi na bazi aminokiselina (Delphan Plus) i huminskih kiselina (Humistar).

Nettle is a highly valued medicinal plant that is still largely neglected, both in terms of nutrition and use for pharmacological purposes. Tinctures, i.e., alcoholic extracts, are becoming increasingly popular nettle products, mainly because they allow better availability of phytochemicals and their stability over a longer period of time. The production of alcoholic extracts is a chemically demanding process that is still usually carried out using conventional techniques, which have numerous drawbacks. The use of green technologies such as ultrasound-assisted extraction (UAE), which is characterized by high efficiency of phytochemical extraction, shorter treatment time, and a much lower environmental footprint, is a suitable and sustainable solution. Therefore, the aim of this study is to determine the influence of the extraction method, conventional and ultrasound (by varying two ultrasound equipment systems), time and ethanol concentration on the extraction of specialized metabolites from nettle powder. Ultrasonic extraction using a probe system significantly contributed to increase the ascorbic acid yield, polyphenolic compounds, and antioxidant capacity of nettle extracts compared to conventional extraction. In addition, when a probe system was used during UAE, significantly less time was required for isolation of individual specialized metabolites compared to ultrasonic extraction in the bath. Ethanol concentration (50 and 80% v/v) also proved to be an important factor in the efficiency of extraction of specialized metabolites, with 80% ethanol being more effective for the isolation of ascorbic acid and pigment compounds (chlorophyll and carotenoids), while 50% v/v for the extraction of polyphenolic compounds. It can be concluded that extraction with the ultrasonic probe system is much more efficient in obtaining higher yields of specialized metabolites from nettle powder in a shorter time (average process duration 5–10 min) both compared to UAE in the bath and classical extraction. However, optimization of the key factors of time, solvent type, and ultrasonic power is necessary to maintain the nutritional quality of the nettle extract in order to obtain a final product with a high specialized metabolites content, antioxidant capacity, and functional value. The future application of alcoholic nettle extracts is based on the fact that these products have significant potential as functional foods and pharmacological preparations for the treatment of a number of but also to strengthen the immune system, mainly due to the rich nutritional composition and high content of various specialized metabolites. The prepared extracts can be safely taken orally by diluting the tinctures with water immediately before ingestion.

Jabučna komina predstavlja organski ostatak ploda jabuke nakon prerade koji se klasificira kao biootpad te ga je kao takvog potrebno adekvatno zbrinuti. Osim već postojećih metoda zbrinjavanja jabučne komine, zbog njenog značajnog nutritivnog sastava, mogućnosti dodatnog iskorištenja, odnosno oporabe su velike. Cilj ovog rada bio je utvrditi fizikalno-kemijska svojstva jabučne komine te mogućnosti njene oporabe. Analizirani uzorci jabučnih komina imali su visok sadržaj ukupne suhe tvari (20%), topljive suhe tvari (13, 5%) te nizak sadržaj ukupnih kiselina (0, 65%), a zbog čega se može smatrati vrijednim nusproizvodom za daljnju oporabu od prehrambene industrije do biotehnologije, a tek onda klasificirati kao otpad i takav zbrinjavati.

Innovative agricultural practices are increasingly focused on conserving resources, reducing negative environmental impacts, and producing food with high nutritional quality and high content of health-promoting phytonutrients. Proper selection of cultivating factors, especially balanced nutrition, can significantly increase nutritional value and result in foods with significant biological and functional properties. The innovative techniques for cultivation of plant species, such as floating hydroponic systems, can also ensure a uniform chemical composition and high specialized metabolites (SM) content through nutrient solution management. Although it has been neglected in human diet, stinging nettle has a rich chemical composition (vitamins, minerals, pigments, phenols and other SM) and can be consumed as a green leafy vegetable. The aim of this study was to determine the influence of different corrections (B1, B2 and B3) of the nutrient solution (NS) during three harvest periods on the SM content and antioxidant capacity of nettle leaves. The B1 and B2 treatments were initially filled with NS prepared independently of the water’s chemical composition and B3 was filled with NS adjusted according to the chemical analysis of the water. After each harvest, the corrections of NS were made as follows: B1 was filled with water, B2 with NS, and B3 with nutrients according to the chemical analysis of NS. Of the nutritional and functional properties, total phenolics (TP), ascorbic acid (AsA), pigment content and antioxidant capacity were analyzed. The highest TP (377.04 mg GAE/100 g), total flavonoid (279.54 mg CTH/100 g), AsA (112.37 mg/100 g) and pigment content, as well as the highest antioxidant capacity (3546.91 µmol TE/L) were recorded in the third harvest, B2 treatment. The results show a significant positive influence of multiple harvesting and NS treatment on the SM content of nettle, confirming this type of hydroponic cultivation as an innovative technique for the production of novel food with high nutritional value.

Cilj rada je bio utvrditi mogućnost primjene lasera kao predtretmana sušenju grožđa. Bobice grožđa tretirane su 100 i 200 mW laserima u trajanju od 60 i 120 s. Za analizu je korišteno svježe ubrano grožđe sorti Traminac i Muškat Hamburg s početnim udjelima vlage od 81, 45% i 77, 25%. Kod obe analizirane sorte dobivene krivulje sušenja se razlikuju ali su sve negativnog predznaka, što ukazuje na padajuću funkciju, a potvrđuje da se radi o procesu sušenja. Kod sorte Traminac primijećen je značajniji gubitak vode tijekom laserskog tretmana nego kod sorte Muškat Hamburg što se može pripisati razlikama u građi bobica među odabranim sortama. Iz rezultata je vidljivo da lasersko zračenje utječe na migraciju vode iz unutrašnjosti na površinu, te se kao takvo može koristiti kao učinkovit predtretman sušenju grožđa koji ujedno ne oštećuju biljni materijal.

As microgreens are increasingly grown as functional food, their cultivation technologies require optimization of factors such as temperature, light and humidity. Quality (wavelength) and photoperiod (duration) are the most important light factors that directly affect yield and morphological properties of plants. Photosynthetically active radiation (PAR) includes wavelengths in the range of 400-800 nm, whereby specific photoreceptors of plant cells absorb blue (400-500 nm), red (600-700 nm) and dark red (700-800 nm) wavelengths. The aim of this research was to determine the effect of supplemental LED's lighting with blue (450 nm), red (620 nm) and combination of blue and red spectrum (50:50) in the photoperiod of 14 h on the yield, morphological properties, pigments and colour content of broccoli microgreens. The research was conducted in a climate chamber with controlled conditions for plant cultivation (25 °C, 60% relative air humidity). Samples of broccoli microgreens were manually cut at the base of the hypocotyl in the cotyledon phenophase at a height of 7.5 cm after eight days. Microgreens of broccoli grown under LED supplementary lighting of blue spectrum and combination of blue and red spectrum showed higher yields (1198 g/m2) than samples grown under red spectrum (1046 g/m2). Broccoli microgreens grown under red spectrum had a longer hypocotil (69.7 mm) than samples grown under blue and combined spectrum. Samples grown under blue light treatment had larger leaf lenght (9 mm) than samples grown under red light treatment and combined light treatment. Most clorophylls were acumulated under blue light (0.920 mg/l) as well as carotenoids (0.410 mg/l) and most colors were accumulated under combined light. Based on the results, it can be emphasised that growing microgreens under supplemental lighting (LED) has a positive effect on morphological parameters, yield and pigment content.

According to the new guidelines for waste management, procedures to prevent the generation of waste and techniques to recover it take precedence over recycling and disposal. Plant food waste (organic residues) and by-products from fruits and vegetables represent a nutritionally valuable source rich in numerous specialized metabolites important for human health. Therefore, the recovery of such by-products into valuable resources is crucial for the production of new food products, especially in order to reduce food waste. The pumpkin by-product is also a valuable source of numerous metabolites, especially vitamins, dietary fibers, polyphenolic compounds and carotenoids, and therefore represents a valuable material for further utilization. One of the ways to produce new products is the drying process, which very often has a negative impact on the nutrient composition of the plant material due to the high temperature and is also energy consuming. For this very reason, innovative pre-treatment methods such as ultrasound and hybrid drying techniques (vacuum-conduction) are being developed. Vacuum drying uses low pressure to evaporate water at lower temperatures, preserving heat-sensitive bioactive compounds such as vitamins, carotenoids, and other phytochemicals, while ultrasound pre-treatment also offers a number of benefits, most notably significantly shortening the drying process and preserving nutrients. The aim of this study was to determine the influence of temperature (60 and 70 °C) and ultrasound pre-treatment (37 kHz, 380W, Elmasonic P 300H, ultrasonic bath 100%) during hybrid vacuum-conduction drying (100 mbar) of pumpkin organic residue on the content of specialized metabolites. Drying processes were performed in a vacuum drying oven VO 200 (Memmert, Germany) at a pressure of 100 mbar. The pumpkin slices were dried to a final water content of 14%. The highest vitamin C content (439.14 mg/100 g DW) was determined in pumpkin samples pre-treated with ultrasound for 5 min and dried at 70 °C ; total phenolic content (1655 mg GAE/100 g DW) was also determined by vacuum drying at a temperature of 70 °C without ultrasound pre-treatment. The β-carotene content was best preserved by vacuum drying at 60 °C with ultrasound pre-treatment for 10 min. In general, all dried pumpkin samples are characterized by high antioxidant capacity, proving that hybrid vacuum drying combined with ultrasound pre-treatment has a positive effect on nutritional potential. In conclusion, ultrasonic pre-treatment had a significant effect on the preservation of bioactive compounds in the dried pumpkin samples, while drying by vacuum (100 mbar) at both combined temperatures (60 and 70°C) showed no negative effects on the nutritional composition of the pumpkin samples. Therefore, it can be concluded that this method of drying and ultrasonic pre-treatment is an efficient way to preserve the nutritional composition of the raw material, thus giving the organic residues the possibility of additional recovery and further use and utilization.

Coffee is one of the most commonly consumed beverages, but after brewing, a large amount of residue is produced, that remains unused and is discarded as waste. One of the priorities of the European Green New Deal is to convert and reuse materials into new value-added products thus significantly reducing waste disposal and its negative impact on the environment and human health. Since the phytochemicals are not completely extracted during the brewing process, spent coffee grounds is very abundant in bioactive compounds (carbohydrates, proteins, lipids, oils, alkaloids, minerals, phenols, etc) some of which may have antioxidant properties. Therefore, it shows a high potential for recovery and can be used as multipurpose material in mushroom growing, soil enrichment, pellet production, and different industries (pharmaceutical, agricultural, food, cosmetic). Using new sustainable technologies, such as ultrasound-assisted extraction (UAE), which enables low energy consumption, faster extraction, and higher yields of antioxidants also helps minimize negative ecological impacts and therefore is classified as a green technology. For this study, the coffee residue was collected after brewing with a catering coffee machine. Samples were prepared from 5 g of spent coffee grounds and as a green solvent 50% and 80% ethanol (v/v) was used. The aim was to optimize the extraction method by determining the influence of different variations of the probe and bath UAE on the content of polyphenolic compounds and antioxidant capacity of spent coffee grounds extracts. The type of equipment, ethanol concentration, time, and amplitude were tested. The highest total phenolics content (TPC) and total non-flavonoid content (TNFC) (835.68 and 477.62 mg GAE/100 g, respectively) were determined during 10-minute extraction with 50% EtOH and a probe system with 60% of amplitude. For the determination of antioxidant capacity, the FRAP method proved to be more suitable than the ABTS method for this type of raw material, and the highest value was observed when using the probe system (20% amplitude) with 50% EtOH (v/v) and 5-minute extraction. In general, the UAE with probe system proved to be a better solution for the extraction of polyphenols from spent coffee grounds than the bath system. This research has shown that different treatments of UAE can have an influence on polyphenol extraction, and instead of being treated as waste, spent coffee grounds can be utilized as a source of bioactive compounds. It is important to conclude that coffee grounds recovery can have many applications, can greatly reduce waste accumulation and be a significant by-product for further reuse.

Hidroponski uzgoj koprive u zaštićenom prostoru omogućuje dostupnost biljnog materijala kroz duži period godine uz veće prinose te bolju kvalitetu herbe u odnosu na uzgoj na otvorenom. Cilj istraživanja bio je odrediti komponente prinosa te prinos svježe herbe koprive uzgajane tehnikom plutajući hidropon u dvije hranive otopine različitog sastava kroz dva roka košnje. Bolji utjecaj na promatrana morfološka svojstva imala je otopina s manjom količinom hraniva (Jensen, EC = 1, 7 mS cm-1) u odnosu na otopinu s većom količinom hraniva (Cooper, EC = 3, 0 mS cm-1). Kombinacije pojedine otopine i 2. roka košnje ostvarila je značajno veći prinos koprive u odnosu na 1. rok košnje (2, 3 kg m-2 i 1, 8 kg m-2).

Demands for healthy, nutrient-rich foods that are minimally processed are on the rise and consumers are paying more attention to the origin of the foods and their functional properties. New agricultural practices are based on providing safe raw materials with uniform chemical composition. This is important for the stinging nettle, which is mostly collected from the wild where it tends to accumulate excessive amounts of nitrates and heavy metals. Previous studies have shown that nettle contains a significant amount of phenols, vitamins, pigments, minerals, proteins, fats, fatty acids, sterols, volatile compounds, tannins, etc. Moreover, numerous pharmacological studies have demonstrated the antioxidant, antimicrobial, anti-inflammatory, antitumor, antidiabetic, antiulcerogenic, hepatoprotective, hypoglycemic, and other properties of nettle. Thanks to its high content of bioactive compounds and proven nutritional and health effects, nettle can be considered an important functional foodstuff so there is a justified reason for placing nettle on the market as a new packaged food product. In accordance with sustainable production and circular economy, it is recommended to use modern food processing (minimal, non-thermal technologies), packaging methods (modified and controlled atmosphere), and materials (such as biodegradable). Appropriate packaging methods and materials can ensure the safety and longer shelf- life of products and help to preserve compounds responsible for biological effects. The aim of this study was to summarize the data from previous research on the nutritional, functional, and pharmacological properties and to discuss the further potential of using, processing, and packaging nettle leaves as a green leafy vegetable in order to popularize this new food product.

Microgreens are becoming increasingly popular with consumers, not only for their exceptionally intense flavor and color, but also as a functional food with high nutritional value and strong antioxidant activity. Growing microgreens in greenhouses, especially in winter, presents a number of challenges, most notably a lack of light. Light is one of the key factors for optimal plant growth and development, for obtaining adequate yields, but also for the accumulation of various phytochemicals. Quality (wavelength) and photoperiod (duration) are the main light factors that directly affect the morphological characteristics of plants and a number of changes in metabolic functions related to nutrient composition and synthesis of specific metabolites (SM). Photosynthetically active radiation (PAR) includes wavelengths in the range of 400 - 800 nm, with specific photoreceptors of plant cells absorbing red, dark red, blue, and ultraviolet (UV-A) wavelengths. Optimization of the key factors of light, quality and quantity, can significantly positively affect the synthesis of various SM of plant, such as vitamins, polyphenolic compounds, pigments and other compounds of high antioxidant activity. The aim of this study was to determine the influence of red (620 nm) and blue (450 nm) spectra and different photoperiod (12 and 16 h) of supplemental light- emitting diode (LED) illumination on the composition of some SM and antioxidant capacity of mung bean microgreens (Vigna mungo (L.) Hepper)). The study was conducted in a climate chamber with controlled ecological conditions (25 °C, 60% humidity) under supplemental illumination by LEDs. Microgreens mung beans were manually cut at the base of the hypocotyl in cotyledon phenophase at a height of 12 cm and the following SMs were analyzed in the fresh plant material: ascorbic acid content (AsA), total phenolic content (TPC), and antioxidant capacity (by ABTS). The highest levels of AsA (61.74 mg/100 fw) and TPC (223.96 mg GAE/100 g fw) in mung bean microgreens were determined by treatment with LEDs in the red spectrum at a photoperiod of 16 hours. During the photoperiod of 12 hours, higher levels of AsA (50.56 mg/100 g body weight) and TPC (191 mgGAE/100 g body weight) were determined by blue spectrum illumination. Quality and photoperiod had no significant effect on antioxidant capacity. Regardless of the different treatments, antioxidant capacity values were generally high, with an average value of 2374.09 µmol TE /L, indicating that mung bean microgreens represent plant material with high nutritional and functional value. The obtained results indicate that proper management and optimization of quality, i.e. light intensity (selection of appropriate spectrum and photoperiod), can significantly affect the nutritional quality of the plant material and improved synthesis of SMs. From all this, it is clear that further research on specific light factors is needed to optimize the cultivation of plant material with adequate yield and high functional properties.

The need for sustainable production of nutrient- rich foods is critical both for environmental protection, mainly to reduce footprint on the soil, water and air, and for human health. Therefore, agricultural practices are increasingly shifting to greenhouse cultivation, where abiotic factors can be controlled and optimized regarding to the specific needs of each plant species. Hydroponic cultivation stands out as a successful growing system that provides a controlled environment, water and nutrient consumption ensuring higher yields, better morphological characteristics and favorable mineral composition. Floating hydroponics is offered as one of the techniques whose main advantages are the elimination of potential problems caused by soil contamination, the possibility of lower water consumption and precise and balanced plant nutrition. Stinging nettle (Urtica dioica L.) is a perennial plant species characterized by the possibility of retrovegetation and multiple harvesting, which makes it interesting for agricultural production. However, it also tends to accumulate heavy metals and excessive amounts of nitrogen from the soil. Therefore, it poses a challenge in terms of questionable plant material for further use and consumption. As nettle becomes more popular among consumers, mainly due to its favorable nutrient composition, high antioxidant and essential minerals content, its cultivation is necessary to ensure consistent chemical composition and high quality. The aim of this study was to determine the effects of nutrient solution (NS) content during two harvesting periods on the morphological characteristics, dry matter and macroelements content of fresh nettle leaves. The experiment was conducted in a heated greenhouse during the fall-winter growing season of 2021/2022. Nettle was grown in basins filled with NS standardized according to Johnson's (EC 1.5 mS/cm). Management of the solution during cultivation was varied as follows: basin 1 (B1) and 2 (B2) were filled with Johnson's solution prepared independently of the water chemical composition while in basin 3 (B3) Johnson's NS was adjusted according to the water chemical analysis. After the first harvest, only water was added in B1 to replace the drop level of NS ; in B2 the initial NS was added ; in B3 the amount of nutrients was added to match the composition of the initial standard solution based on the NS analysis performed after the first harvest. Two harvests were carried out (Nov 3, 2021 and Jan 11, 2022), after each, morphological and chemical analyses were conducted and the results were statistically analyzed. The results show that both factors, NS variation and harvest period, have a significant influence on the morphological characteristics, yield and macroelement content of fresh nettle. In the first harvest, values for nettle plant height (28.53 cm), leaf length (7.57 cm), width (6.07 cm) and yield (1.26 kg/m2), as well as for N and P (5.83% N dry weight (dw) and 1.15% P dw) were generally higher regardless of the solution variant. The second harvest resulted in higher dry matter (22.12%) and K (4.16% K dw) values. The lower values of all morphological parameters and macroelements found in nettle in the basin supplemented with water prove that in case of multiple harvests, correction of NS is necessary to obtain adequate yield and nutritional value of the final product.

Nettle (Urtica dioica L.) is a perennial plant used as a medicinal herb and also as a food. Besides numerous phytochemicals, nettle is great source of macro and microelements which are important for human health. In the last 2 decades, global world population is more and more aware of problems caused by climate change which affect both the decrease in yield and the lower quality of the final product. Therefore, hydroponic production is good solution for optimal nutrient supply in order to produce nutritionally high quality nettle. In this way excessive application of nitrogen is avoided and reduced negative effect on other nutrients and quality itself. The aim of this research was to determine macromineral compostion of nettle in hydroponic production system according to different nutrient solutions in order to obtain the highest possible mineral status. The experiment was conducted in a greenhouse following randomized complete block design with three replicates. Four different nutrient solutions (Johnson, Jensen, Larson, Cooper) which differ in EC value (1.72, 2.34, 2.50 and 3.42 mS/cm, respectively) were tested. Nettle was sown on 11 March 2021 in polystyrene plates filled with perlite and placed in basins filled with nutrient solutions after germination. Harvest was performed manualy on 20 May 2021. Samples were first dried, then homogenized which was followed by digestion in the microwave oven with HNO3 and HClO4. Phosphorus was determined spectrophotometrically, potassium phlamorphotometrically and calcium and magnesium by atomic absorption spectrometry. Nitrogen was determined by Kjehldal method. Results showed differences between nutirent solutions and harvest. The content of macroelements varied as follows 6.15-7.14 % N DW, 0.87-0.93 % P DW, 4.21- 4.75 % K DW, 4.95-5.40 % Ca DW, 0.72-1.13 % Mg DW.

Tradicionalne sorte kruške na području sjeverozapadne Hrvatske zastupljene su uglavnom kao pojedinačna stabla na okućnici, vrtovima, parkovima, uz ceste ili rubove šuma. Njihova stabla većinom su u razdoblju starenja ili odumiranja, a plodovi pojedinih sorti odlikuju se dobrom kakvoćom. Cilj istražavanja bio je utvrditi fizikalno-kemijska svojstva 13 najzastupljenijih tradicionalnih sorti kruške na području sjverozapadne Hrvatske ('Badnjarka', 'Citronka', 'Dugačka', 'Dugodrška', 'Galonka', 'Kozolova', 'Krasanka', 'Rokovica', 'Stršljenka', 'Tepka', 'Zelena slatka', 'Zimka', 'Žutica') te izdvojiti potencijalne sorte za uzgoj. Nakon provedenih analiza (masa, visina i širina ploda, indeks oblika ploda, tvrdoća ploda, broj i masa zdravih sjemenki, udio topljive suhe tvari, udio kiselina, omjer topljive suhe tvari i ukupnih kiselina, pH vrijednost), utvrđeno je da se sorte značajno razlikuju u istraživanim svojstvima. Veličinom ploda te skladnim odnosom topljive suhe tvari i ukupnih kiselina istaknule su se sorte 'Krasanka' i 'Dugačka'. Sorta 'Tepka' istaknula se visokim sadržajem topljive suhe tvari što ju čini vrijednom sirovinom za proizvodnju rakije. Temeljem dobivenih rezultata može se zaključiti kako tradicionalne sorte kruške predstavljaju potencijal za uzgoj i preradu, a važno ih je očuvati kao izvor genetske varijabilnosti.

Tomato (Lycoperscion esculentum) is an annual vegetable crop of the Solanaceae family. It can be consumed as fresh food or processed in the form of pelee, concentrate, juice or ketchup. Potassium activates enzymes and regulates permeability of living membranes. The goal of this research was to determine the content of potassium in fresh tomatoes and tomato products. Tomato sampling was conducted on 3 sales places in Zagreb, including fresh grappolo tomatoes, fresh cherry tomatoes, ketchup, double concentrate (28-30 % DW) and organic tomato pelée. In order to determine the content of potassium, the grinded samples were digested with concentrated HNO3 and HClO4 in a microwave oven, potassium is determined by flamephotometer. The content of dry weight ranged from 4.2 to 30.4%. Statistically the highest potassium content was found in fresh grappolo tomatoes (7.5% K dry weight and 1783 mg K/100 g in fresh weight). Slightly lower potassium content was determined in fresh cherry tomatoes and peeled tomatoes, while in ketchup was statistically the lowest (1.97% K dry weight and 65 mg K/100 g in fresh weight).

Climate changes (global warming, drought) exacerbates food production problems and poses a global challenge to modern agriculture. One of the main objectives of the strategy of European Union is to achieve a carbon-neutral circular economy, which includes, among other things, a series of strategic plans in agriculture, such as the increased use of sustainable agricultural practices. Indeed, outdoor vegetable production is increasingly exposed to many risks, making it necessary to introduce modern farming methods and change the current crop production strategy. Hydroponic crop production offers itself as a suitable solution to overcome the above-mentioned problems, mainly because of its advantages, which range from good management of natural resources to rational water use, avoiding nutrient losses from the rhizosphere, etc. More efficient use of water and nutrients will result in higher yield and the nutrient quality of the raw material can be controlled. It is important to emphasize that the above technique promotes balanced and rational fertilization and water use, with the aim of minimizing nitrate uptake, and is therefore suitable for ecologically sensitive areas. Similarly, there is a growing need for new food sources rich in valuable bioactive compounds important for human health. Nettle, a species often considered a weed, is rich in phytochemicals that make it valuable from a pharmacological and nutritional perspective. It grows wild in nature, but in hydroponic cultivation (avoiding water and/or temperature stress) it is possible to obtain a final product with a uniform chemical composition and a high and regular yield.

Razvojem prehrambene tehnologije sve više se počinju implementirati moderni postupci i tretmani procesiranja proizvoda. Naime, moderne tehnike, poput ultrazvučno potpomognutog tretmana pripadaju u neinvazivne metode, čija se glavna prednost očituje u skraćivanju trajanja procesa i očuvanju nutritivne kvalitete gotovog proizvoda. Stoga je cilj ovog rada bio utvrditi utjecaj ultrazvučnog tretmana, kao i različitog vremenskog perioda obrade ultrazvukom na sadržaj β-karotena u soku klementine. Ultrazvučni tretman značajno je pozitivno utjecao na sadržaj β-karotena prilikom čega je čak 81 % veći sadržaj utvrđen u ultrazvučno tretiranim uzorcima sokova klementine u usporedbi s kontrolnim uzorkom. Od istraživanih vremenskih perioda obrade, ultrazvučnim tretmanom od 15 minuta dobivene su najveće vrijednosti β-karotena.

Prema prethodnim istraživanjima, tradicionalne sorte jabuke bogate su polifenolnim spojevima, a također imaju i zanimljiva fizikalno-kemijska svojstva koja su često važna potrošačima. Cilj ovog istraživanja bio je utvrditi fizikalno-kemijska svojstva ploda (masa, visina, širina, indeks oblika, boja, tvrdoća, indeks razgradnje škroba, indeks zrelosti, udio topljive suhe tvari, ukupne kiseline, omjer topljivih topljive suhe tvari i ukupnih kiselina, pH, svojstva sjemenki) te količinu fenola u kožici i mesu ploda 25 različitih tradicionalnih sorti jabuke iz Hrvatske. Rezultati istraživanja ukazali su na različitost fizikalno-kemijskih svojstva plodova istraživanih sorti jabuke. U plodovima su utvrđene velike količine flavan- 3-ola, dihidrohalkona, fenolnih kiselina i flavonola, dok su u kožici dodatno utvrđeni i antocijani. Statistička analiza rezultata korištenjem analize glavnih komponenata pokazala je moguće grupiranje istraživanih sorti. Tradicionalne sorte jabuke treba očuvati jer predstavljaju vrijedan izvor polifenola i raznolikost fizikalno-kemijskih svojstava koje potrošači cijene.